The grip frame is brass, mounted to steel. Not sure about the barrel unscrewing. I'm not by the gun right now, but I'll look for signs of screw threads when I get home. If it helps, the post that the cylinder slides over has what appears to be square, or acme threads, likely grease grooves. There's also a number 32 stamped on that post. I've seen others that look smooth. Also, on the cylinder other than "Engaged 16 May 1843" is the words Patent N, with no numbers at all. I'm in the machine tool business and the care and detail in the machining looks quality to me. Keep the ideas coming......CSI fun.